i posted this in the tech section, but got no responses. figured i would post here in the hopes of getting some help.

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howdy

technically this isnt a harley question, since the bike in question is a 1976 honda cb750. but im assuming most hydraulic brake systems work the same, and troubleshooting would be similar.

ok, so i recently bought a 76 cb750, and the front brake lever doesnt squeeze much. at all. on all my other bikes (harley and 2 suzies) i can grab a full fist of brake; on this one, i get maybe a half inch of travel at the end ball of the lever -- and it's *really* tight feeling. takes a LOT more effort to squeeze than the other bikes. the brake itself seems to work, but not nearly as much as id expect it to.

any ideas what would cause this? ive never troubleshot a hydraulic brake system before, so consider me a total noob. i will probably end up bringing it to the shop and have them look at it, but i wouldnt learn anything that way.

thanks in advance.

 

Is the front brake disc? Sounds like your caliper piston is hanging up. Rebuild your caliper, bleed the system and you should be fine.

 

yeah, it's a single disc. ive never worked on brakes systems before, so im clueless to what a rebuild entails.

 

Keep the fluid off of paint and plastic just in case. Rebuild shouldn't be that difficult but surfaces must be clean and I would at least look at a manual or a break down of the kit parts that I ordered to do the brake job. Should be a kit. I would also price everything --sometimes things are almost as cheap to replace instead of rebuild.

 

If you are not sure about how to rebuild the caliper, it might be better to just remove it and take it to a dealer or indy and have them rebuild it. Installing it and bleeding is easy.

 

just for the hell of it, try bleeding the brakes 1st, bleed it enough so you do a complete flush. Thats an old bike with old fluid in there so you need to change it anyway. You got nothing to lose but a can of brake fluid and a little time. good luck

 

If bleeding/flushing doesn't work, I'd prolly take the caliper apart and try to clean it up. Whatcha got to loose? If it doesn't work or you screw it up, you gota buy a kit or new one anyway. Just pay attention to how it comes apart, shouldn't be that hard.

So why did you buy the bike? What shape is it in? Project? Collector?

 

Not to knowledgable on brakes yet, but does the brake line have a housing like clutch cable? my clutch cable was acting the same way, turns out the dummy who owned the bike before me ran a bolt holding the exhaust clamp into the cable pinching the housing. brake line similar construction? or just hardlined?

 

Naw,,,,,,,,,,,,,,,, its like a hyd system.. fluid runs through it...

 

I like the way this man-----^ thinks! Even if you don't want to tackle the repair job yourself, this is a good opportunity to check out the inner'ds...

Learning is a process of discovering what you never thought you could do, isn't as difficult as you once believed. Fear is for sissies. Jump into it cautiously, then own the reward of accomplishment! Mistakes are just steps which raise your experience level...

Hydraulics are hydraulics. Piston pushes fluid mechanically by pulling the lever at the hand grip through a tube to another area, which then in turn pushes another piston to achieve compression of brake pads against the brake rotor. Blockage at any point in the system can give you the feeling you describe. Thick sludge from old brake fluid which has absorbed any available moisture can cause the master cylinder piston to freeze or lessen it's travel. Rubber brake lines can seperate on the inside and present a flap of rubber inside the line that causes blockage when the pressure is applied. And as mentioned, the caliper piston on the other end can also be the point where movement is limited for a couple of different reasons. Unhindered movement of mechanical parts, and free flowing fluid in the lines are the essentials to any hydraulic system...

Different brands might try to make their parts proprietary, but the mechanics and theory of it all still work the same.